    1. Technical Field
The present invention relates to a technique of a head-mounted display device.    2. Related Art
Hitherto, there has been known a head-mounted display device (HMD) which is worn on a user's head. For example, JP-A-2005-38321 discloses a video see-through type HMD in which an imaging section capable of imaging an outside scene through a supporting section slides up and down with respect to the HMD.